Modern Mining May 2021

EXPERT VIEW

Commitment and training vital for mining concrete works Concrete plays an integral role in any mining operation – above and below ground – to sustain the mining process and ensure the safety of miners. But for optimum mining concrete works there are some specific elements to consider, says John Roxburgh , senior lecturer at the Cement & Concrete SA (CCSA) School of Concrete Technology.

H e says the robust and durable nature of concrete lends itself well to any mining project with strength, durabil- ity, ease of application, availability, low initial cost and extremely low life-cycle cost other positive factors among con- crete’s other benefits. Areas of application are wide-ranging and include headgears, shaft linings and supports, tunnel supports, roads, lining of ore and waste passes, and as backfill. “Concrete and cementitious materials provide vital support for mining’s massive tunnels which can extend over several kilometres underground. Concrete lin- ings also have to cope with the passage of millions of tons of rough materials tum- bling down through ore and waste passes, as well as severe shocks from blasting. Self-compacting concrete is also playing an increasingly important role in mining,” Roxburgh states. “But achieving successful and safe concreting works in mining calls for spe- cial measures. For example, the concrete

must be easy to mix, transport, and place under difficult conditions and often extreme temperatures. The concrete works will need to be structurally sound, and the finished product must require little to no maintenance after completion. And, most importantly, in a mining environment, it is crucial that concreting is done right – the first time. Failures can not only cause dev- astating losses in production but also in lives,” says Roxburgh. Key components He says there are three key components to proper concrete applications. “Firstly, there must be a sincere and committed intention to get the project done correctly, right from the outset. From top management, right down to the labourers placing the concrete, there must be a passion for perfection. Management, supervisors and foremen, all need to show an energised willingness to attain maximum performance in concrete projects. “Secondly, skills and selection of tools and equipment, are also important. Placing concrete is nearly always done under time pressure – typically, there are only three hours to transport, place, compact and protect the concrete. The right skills, tools and equipment will save valuable time and reduce pressure, resulting in a better product.” Importance of training Roxburgh also believes training is vitally important. “Concrete technology educa- tion provides an essential understanding of how concrete works: of its plastic and hard- ened properties, along with the knowledge of tried and tested best concrete practices on site. Training plays an essential part in the quest for proper concreting so it is important for mining engineers – whether electrical, mechanical, or in other indus- try spheres – to acquire proper concrete

Index to advertisers AECI Mining Explosives 12 Allied Crane Hire 25 Belaz IBC Brelko Conveyor Products 43 Ifm 5 Kemach OBC Maptek 41 MMD Mineral Sizing IFC Multotec Group 33 Shell 3 Vega 7 Vermeer Equipment Suppliers OFC Weba Chute Systems 9 Weir Minerals Africa 21 Wirtgen 4 Zest Weg Group 37 The School of Concrete Technology has for more than 40 years been helping mining staff meet qualification requirements with its bespoke “SCT30 Concrete Technology” course. The intensive five-day course, now presented online, carries five CPD points and cover subjects such as properties of concrete including its mix, transport and production; extenders; aggregates; placing; curing; formwork; reinforcement, and repair of blemishes and defects, among several other topics.  John Roxburgh, senior lecturer at CCSA’s School of Concrete Technology. technology education. It is the engineer who leads mechanical, electrical, civil, or chemical installations and, in nearly all these cases, there will be some type of con- crete works involved, such as foundations, plinths or floors, right at the beginning of the project. Getting the concrete works done correctly – and on time – will start such projects off on a good footing,” he says.

Concrete and other cementitious materials provide vital support for mining’s long tunnels which can extend over several kilometres underground.

44  MODERN MINING  May 2021